Magnetic rail brake



Nov. 21, 1939. c. c. FARMER 5 MAGNENC RAIL BRAKE 2 Sheets-Sheet l Filed Oct. 19, 1937 NVENTOR l GLYDE @.FARMER BY 9% //df/ ATTORNEY Nov. 21, 1939. c. c. FARMER MAGNETIC RAIL BRAKE Filed Oct. 19, 1957 2 Sheetg-Sheet 2 INVENTOR A GLY DE C. FARMER ATTORNEY PatentedvNov. 21', 1939 UNITED l MAGNETIQ RAIL BRAKE Clydeo Farmcr Pittsburgh-ra.,

assiginorc-to/Eh WestinghonsefAir Brake Company, Williieldingg,f Pa.,l a corporation of Pennsylvaniai Apllilvication Octoberf19, 1931, Serial No. 1691.187! '7- Claims. (cuss- 165) I This invention relates to rail brakes, such' las magnetic rail brakes. and hasparticular relation to means for mounting and supporting-rail brakep v shoes on Wheel trucks.

In railwayacars, particularlyk street railway` cars, the Wheeltrucks for the carsare commonly of the type in which the Aside frames ofthe trucks are resiliently supportedby springs onl af xed orl unsprung' part of the truck, suc-h as the journal boxes associated- With the Wheel; axies.` In such a type of Wheel truck the rail brake shoes cannotbe suspended from the sidey frames, ofthe Wheel trucks, because the side frames ofi' the Wheel trucksmove rtoward and away H*from* the associated track rails withv variations in loadv on the Wheel trucks so that the rail'brake shoes will not be maintained normally at a substantially constant 'elevation above the track rails," which is desirable in order Vto prevent undesiredicontact of' the rail brake shoes With the track rai1s.` Furthermoradue to the construction and arrangement of parts 'in such a Wheel truck, itv is diicult if not impracticable to sus,- pend the rail brake shoes from van unsprung part of the truck, such as the journalboxes. ,l `In 4the casel ofk the type o'fxwheel truck mentioned above, there is therefore a need for-gan" improved simple andl relatively inexpensive n'ieansv for so mountingn and supporting' a yrail brake shoe on the Wheel truck that the rail brake shoe is maintained at a substantially'constantj elevationr above the trackv rails for' any load on the wheel truck; and the pro 'sion ofv` such is the principal object of myA present invention.

Another object ofmy invention is to provide means forl supporting `a rail brake shoe on'v a wheel truck, ofthe typedescribed, so as to main-Y tain the rail brake shoe normallyat a substan-` tially constant elevation above the trackl rail for any load on the Wheeltruckwithout inter-` fering in any Way With the usual application ofthe. rail brakeshoe tothe rail.

The above objects, andv other objects of my` invention Which will be made apparenty in thesubsequent description" ofV my invention, may-beattained by various embodiments thereof; three:

of which are illustrated in the accompanying y drawings, wherein- Fig. 1 is a broken diagrammatic view, showingy a Wheel truck and an associated rail brake shoe,-

together With one embodiment of my` invention" for maintaining a substantially constantlnormal' elevation of a rail brake shoe above an associated track rail,

Fig. 2 is a fragmentary plan view showingfin further 'demn-meconstructmnof vthe mechanism' shown in Fig. 1

Fig.` 3 -afdiagram which demonstrates the operationoifthe embodiment of my invention y shown infFi-g; 1f, 5

Fig. iisa fragmentary diagrammatic View,l showing another embodiment of myinvention, the mechanism for'supporting only one end of the shoe being shown',

` Fig. 5 is a diagram which'demonstra'te's the 10 Fig. v6f'isv afragmentarydiagrammatic View showing# a third embodiment of my invention, mechanism-forsupporting onlyv end vof the rail 15 brake shoer beingshown; and

' Fig; 7 is a sectional view;l taken on the line 1-1 off Fig-L' 6,7 showing'V infurtherv detail the construction of the mechanism shown in Fig.y 6.

'y .Erfnlzodimen-trshown in.v Figs; 1 and 2` Referring'to Fig.' 11 of the drawings, there is shown vin outline `form a- Wheell truck comprising a1 front v'vvlfieeleand-axle unit and'` a rear wheel and-axlefuni't, the Wheels I0` and Il' of the front 25 and lthe ,rear laxleunits being adapted to roll along a track rail'IZl The Wheel truck further comprises a journal boxe I3 for each axle on whichitlieoppositeends ofI the 'truckf side frame I5 are resiliently'supp'orted' as vby'a plurality' of 30 interposed truck# springs I4; illustrated' as of the coil type.-

The sid'e'frame I5.` of'the truck has formed at each-end ak so.called pedestal jaw I6, the spaced side niembersof which s'traddle the journal box 35 I3 and'. move slidablys'inv vertically. extending grooves 1:17 vformedz on the opposite sidesr of the journal box.- I3.' f

When the car i-sr'empty and'. the Wheel truck carries: a so-'ca-lled empty load; the trucksprings 40 M; are compressed a, minimum amount and the side frame I5 is:- raiseda maximum distance away-'from the track railk lf2.Y Asthe load on the car: and' consequently that Lon the truck side fra-mel5 increases, vthetruck springs I4 are iny4:5

creasingly:l compressed'V andthe side frame I5 correspondinglylowers toward thetrack railv I2.

` Accordingtolmyf invention, I vprovide two pairs offcooperating l'eve'rs 2-I: and 22, for supporting and! automatically maintaining opposite' ends 50 respective-ly.. offa" rail: brake .shoe 23V at a substantijallyconstant level or elevation above the track rails-I2. fon. anyA load. on the car, thatfis, for'xanyiposition ofthe.truckside frame I5 relative to: .they trackcrail'. Iti should be understoodl 55 journal box I3, and theV opposite end of they lever 2| is pivoted on a sprung partuof the truck, such as the side frame I5, by a pin 2l fixed to or secured in the`sidelframe-'EI'5II -Aslot 28 is provided at the -end` of* lever 2| v'tlnfollfgh which the pin 2'I extends in order to'ajccommo-L date the variation in distanceggbetween the two pins 26 and 2l, as the lever 2| is pivoted in a, clockwise direction, that is, pivoted downwardlyY through `an angle upon Y downward movement of the truck side frame I5.

, As showninFig.- 1, the pin-Zlis xed to the truck side frame at a point `above; the horizontal line through the pin 23 carried.Y ongajournal` box I3, so that when the vehicle .or car is empty, the levervZlIfis at an angleto-thehorizontal. The angleY of the lever 2| to the horizontal may vary according to the amount of movement of` the side frame of the-trucktoward the track rails .when theload on the truck yis increased from emptyV load to full or maximumload.` The angle ispreferably onefhalf of the total angle throughwhich the leverz2| moves when the g side frame I movesdownwardly in response to an increase in the load on theftruckrfrom empty load to full or maximum load. .The reason for this disposition of thev lever 2|y will be made apparent hereinafter. y l v Y, V

As will be seenin Fig. 2, the lever 2|,has a U-portion 3| therein to provide space Ibetween thelever 2| and :the side frame |5.for the lever 22 'which isy relatively short. comparedftq the lever 2! and pivotedl on arpin' 33 `iixed tothe truck side frame' I5. The pin 33 is in spaced re.

lation to and on a yhorizontalline with the pin 2.- A laterally projecting pin V3I|f formed .on

or attached to the lever 22 ,at a point between the ends thereof extends into. and is ablyrin a slot `32 in the lever;2.|.-;. Y

A coil spring 36A is lprovided* for resiliently `sup-` porting one end of the rail brake shoe23 from the free end of the lever 22. The4 spring 36,"is

illustrated for simplicity as havinga hook at the upper end thereof which Jengagessin an opening 3"! at the free end of the lever 32 and a hook at the lower `encl which engages iny an` opening 38 in a supporting lug 39 formed on or attached to the. rail brake shoe 23.

The levers .2| and 22 are so arranged `and so proportionedv in length ythatthe distance fromf the pivot pin `2t, on the journal box I3 to the pivot pin 34 on Ythelever- 22` bears the same ratio to the distance from the opening 3I'at the. end of the lever 22 to the pin 34 as vthe distance` from ther pin^34 to the pin 21 bears tothe dis tance from the pin 34 to the pin 33.- The rea-r son forv the proportionalityV of these moment arms of the levers 2| and 22 will be made apaparent hereinafter.

.The rail brake shoe "23 is illustratedl as of' the magnetic. -type having a magnet winding. :,IIII

which, when energized, causes the rail brake shoe 23 vto be magnetically attracted vinto frictional ,eontact with the track rail I2 to"` eiect a retard-1- `merals. In Fig. 3, with the wheel truck carryingr-empty load, the levers 2| and 22 occupy the positions shown by the solid lines and the rail brake shoe-23 correspondingly is supported "fat fa -certainelevation above the associated track rail.

A s `theloadon the car and thus on the wheel truck yincreases and the truck side frame I5 moves 4correspondingly downward toward the track rail, `the pivot pin 34 on the lever 22 moves a; lesser dista'crrceV downwardly compared to the amountfof `downward movement of the pins 21 and I33, the amount vwhichl the pivot pin v31| moves downwardly comparing to the amount of downward movement of the pins 2'I and 33 in substantially ,the same ratio whichv the moment armonthelever '2| from the pivot pin 26 to the pivot pinV 34 bears tothe moment arm from the pivotV pin 26`to the pin .27.' It will, therefore, baapparent that as the side frame I5 of the wheel'y truck lowers toward the track rail with increase "in load, ther two levers 2i and 22 rotate in'QDD'osite directions so as to decrease the angle of` separation therebetween.`

Now'assinning that the'wheel truck carries one-half of maximum or fullload, the pivot pins 21 -and'33 will be at the level of the'pin 26 on the journal box, and thusthe levers 2| and 22 will be simultaneously in `a horizontal position. It will be r apparentupon analysis that, due to the proportionality of Athe'moment'arms of the levers 2| and) 22 on opposite sides of the pivot pin` 34,; the outer or free'end of the lever 22, from whichjthe rail brake shoe 23 is supported, is maintained at its original elevation and, therefore, that the railbrake shoe 23 is also maintained atitsnormal elevation above thetrack ran l2. Due to. theshifting of thefleverzz to' the horizontal position" from va position at an angleto the horizontaLthe free end of the lever 22l `may shift slightly to the left from the position shown bythe solid line, but the amount of such movement is not such as to cause the rail brake shoe 23V to be appreciably raised.

Assuming that the load on the wheel truck is increased to full or maximum load, the side frame I5 of the wheeltruck and, consequently, the pivot pins 2l and 33 4move downwardly a total-distance D belowtheir positions for the empty load on the car and the levers 2l and 22 correspondingly assume the` positions indicated by Athe broken lines. Itis clearly apparent from Fig. 3 that the two levers 2| and 22 havechanged their angular vrelation `without causing a change inthe elevation of the outer or free end of 'the lever 22 and `thus the rail brake 23 is at the same elevation above the track 'rail for full or maximumgload on the wheel truck as it was for empty and halfl load. Consequentlypit will be seen that the rail brake shoe will be supported at a substantially constant elevation above the trackrail-IZ for any load on the'car truck over the range from empty load to full or maximiml-loaclf. f i

Yloadto fullload., l

It will thus be apparent that the pin 41 moves on a vertical line correspondingy to the. chord vi of the arc of travel .of the long 'arm of the` bell-l f, crank lever y4 I, as it is pivotedI in -a ,counterclock- .A .wise .,direoton, Athat is downwardly, with @naine 2,180,820, Y. l y

ment of` the free end of thelever 22 `on a ,hori-l zontalline, which IdisplacementLwould eecta slight raising of, the rail `Vbrake shoe,vis limited to the slight amountoccurring when .the two levers v2 I land l22 vare bothin a horizontal L position;

Referring to 'Fig-f4` ofthe drawings, a second embodiment of my invention yis shownwhich comprises a type of lever mechanism, yforvsupporting the rail brake shoesgdiie'rent from that shown in Fig. 1. `The leverme'chanism for each end of the rail brake shoe,v comprises 'tWo bell- The ybell-crank lever 4I crank levers 4I and 42. is pivoted Wat the fulcrum thereof .onan'` unsprung part of the wheel truck, such as thejournal box I3,'by"afpin44 in` alug 45 formed'onfo'r YAattached to the journal box -I3, and the bellcrank lever 42 is lpivote'd 'at the `fulcrumthereof on a sprung part of thev wheel-'truck-'such as the side frame'IE, by a'pin 46 fixedto the side frame.

crank lever `4Ifis pivotallyA connected to the side frame I5 as byva pin 41 xedto'theside frame and received ina slot 48 at th'e end of the'lever arm.

The-outer endv of the otherlever arm *ofv the bell-cranklever 4I and the vouter-end of` onel of the lever. arms of the bell-"crank leverr42 vare connected'by a link 5I, one end. of the link 5I being pivoted 'on the arm of the bell-:crank lever 4I as byafpin 52 and the' opposite end of-thelink 5I being pivoted on thenarmpf th'e'bell-crank' lever 42 'as by a pin"54..'. Theirail brake" shoe 23Y is suspended; at one end, on theouter end'of the other arm of the bell-crank lever 42 thro-ugh thel medium of a coil spring lili.y

The arms of each of -theIbell-crankrlevers 4I. v. and 42 are preferably at righta-ngles to each other. u

and one arm is relativelyilongcompared-to the otherarm. .The .relatively long` arm `of the-bellicrank lever 4I -is 4pivoted to the side frame I5 by the pin 41 and the rail brake -s'hoe'23 vis suspended from the outer `end ofthe relatively long. arm of. the bell-crank lever 42.- v The bell-crank levers 4I and 42-n1ay be. of the same size but not necessarily, it being' essential.. onlythat the corresponding long-and short arms-r of the two bell-crank levers be proportional, in,I

length.

For the same reason asfin the'case of the lever 2I of Fig. 1, the longarm ofithezbell-crank lever 4I andthellong arm of the bell-crank lever'42,-

are disposed at an angle to 'the-horizontal when* wardly toward Athe track rail inresponse to an increase in load `onthe Wheel VEmbodvz'me-rl.'tv shown in L l truck from,enflpty-qy crease `in. ,fload., Asawresult, thegangular position of the bell-crank lever 4I, and accordingly that ofwthe. bell-crank lever.v 42, corresponds closely overV theientire range :of vloadvariation'to the position of the side framef'l'. f i w. i f

The operation of the embodiment shown .in Fig. 4.is morereadily understandable by reference tovthe diagram shown in-Fig.. 5', in which ythe variousfbell-crank levers and other parts are designated by corresponding "reference numerals.

-Itxwill be. observedthatwith,empty'load on the Wheel,v truck', the bell-:crank levers -4I and 42 assume respective; Lpositions l'as .shown by the solid linea-ther rail ybrake shoe y23 .being-thus supported ataxcertain desired. elevation above the trackrail I2# f v f l a l As the 1oad,on.th'e.wheertruck increases,` .the sidep-.frame-.IS is correspondinglyv ylowered toward the-.track rail `and thusztheqbell-crank lever 4l-.isfpivotal1y moved on the pinl 44'xed on the journal box I3. At the same'tinia'the bellcrank lever -42 is` rotatedzpivotally on the pin .4.5i

whichr is being lowered together and simultaneously with .the side'framel I.5..\ i.. r

'.Sincaas-previously stated,';.the longarm of the bell-crank.I levers 4I and vv42 are-disposed at an angle to zthedhorizontal which is'one-half` the" 42j are both in a horizontalposition.L Thus, the

outer end of the longjarm' of the gbell-'cr'ank lever-,142 supportingfthe brake shoe'23 vis moved slightly: in-the left-hand direction' from the normal vertical line ofsuspension of thetrail brake shoe, but remains at thev same elevation asffor an empty `load von the .wheel truck;A and consequently lthe railV brake shoelikewiseremains substantially at, its-,original elevation above the trackraiL. .f f'

When the wheel truck carries afull or maximumfloadythe pivot pin 41` of the bell-crank lever- 4I and the fulcrum pin 46 for the bell crank lever 42 are lowered toward the-rail a total distance indicated by the letter'D, and the bell-crank levers ,ITIIy and 42 correspondingly assume respectivef positions,I indicated-'by the brokenv lines.

Asjyvill be clearlyseen iny the diagramythe long arm of the bell-crank lever 42 is at the same angle belowlthe horizontal =line-With maximumk loadion` the wheel truck as it-,was above the. horitruck,;and thus the pointy on the long arm of the bell-jfcrank lever 4Z from which 4,the railV brake shoe y 2i-3 is,v suspended lis in the identical position which itLWas under empty load conditions.

yItY,,will- .tliu's ybe apparent that with both ends of the. rail brake shoe 2,3adjustably supported in` Jhe mannen above described, they rail brake shoe-i Will', be `maintained at a substantially constant elevation above the ytrack rail foriany load on zontalline for empty `load carried by the wheel thewheelctruck overthe entire; range between emptyand full'load; ff Embaieht ySadam ih rjigfe me 7 Referring to Figs. 6.. a. r1,d v7l pf the drawings, a third embodiment of my invention is shown for supporting; the, rail brake shoes at a substantially constant elevationy above an associatedtrack rail.

Themechanism shown,.comprisesv Atwo `laterally spaced Vcams 6I and 62 thatv are-keyed or otherwise suitamy ,fixed on :a rodforlk sharm?.` 'which is formed in two spaced walls. of the truck side frame I5. i

Connecting the two spaced vertical walls of the side frame I 5 is a horizontal shelf 68 with which the cams 6I and 62 cooperate in a manner to be hereinafter pointed out.

Fixed to the shaft 63 at apoint between the cams E! and 62 is a short lever 69, the outer end of the lever being formed as a clevis to receive pivotally one end of a link 1I, the other end of which is pivotally connected to the outer end of one arm of a bell-crank lever 13. The bell-crank lever I3 is pivoted at the fulcrum thereof on an unsprung portion of the wheel truck, such as the journal box I3, as by a pin 'I4 in a lug 45 on the journal box, The outer end of the other arm of the bell-crank lever 13 is pivotally connected to a sprung portion of the vehicle, such as the side frame I5 of the truck,as by a pin 'I6 xedto the lside frame and engaging in a slot I1 at the end of the lever arm.

For the same reason as in the case of the lever 2I of Fig. 1, the arm of the bell-crank lever 'I3 which pivots on the pin I6 lis disposed at an `angle to the horizontal when the wheel truck carries empty load. Thus the pin 'I6 moves downwardly on a vertical line corresponding to the chordof the arc of movement of the lever arm of the bell-crank lever 13, thereby causing the bell-crank lever 'I3 to correspond closely in angular position to the position of the side frame I5 over the entire range of load from empty load to full load on the wheel truck.

The rail brake shoe 23 is suspended, at one end, from the shaft 63 by means of a coil spring 19 which is suitably formed at its upper and lower end for attachment to the shaft and to the rail brake shoe. A slot 8l is provided in the shelf 68 to permit the shank or stem portion at the upper end of the coil spring 19 to extend upwardly therethrough and between the cams 6I and 62 to the shaft 63. i

The bellecrank lever I3 and the cams 6I and E2 are so designed and so arranged that when the truck side frame I5 moves downwardly toward the track rails according to the increase in load on the wheel truck, the bell-crank lever 'I3 pivots on the pin '14, in a counterclockwise direction, to cause a corresponding rotation of the gcarnsl and 62 in a counterclockwise direction,

as viewed in Fig. 6, the degree of rotation ofthe cams 6I and 62 and the contour of the cams being such as to support the shaft 63 on the shelf 58 of the side frame I5 at a constant elevation despite the lowering of the side frame I5. Obviously, the slots 64 in the walls of the truck side frame I5 enable the shaft 63 to move with respect to the side frame and guide it in a vertical line so that the line of suspension of the end of the rail brake shoe remains unchanged.

In view of the fact that the rail brake shoe 23 is suspended at each end from corresponding shafts 63, it will be apparent that the rail brake shoe 23 is maintained at a constant elevation above the track rail for any load on thev wheel truck over the entire range from empty to full load.

Summary summarizing, it will be seen that I have disclosed three embodiments of my invention for supporting and automatically adjusting the position of a rail brake shoe to maintain a constant elevation thereof above the associated track rails Ifor any load on the wheel truck over the entire range vfrom empty to maximum load, without in any way interfering with the application of the rail brake shoes to the rails in the usual manner.

While I have disclosed only three embodiments of .my invention, it will be apparent that various omissions, additions or modifications may be made in any of the embodiments without departing from the spirit of my invention and it is, therefore, not my intention to limit the scope of my invention .except as it is necessitated by the scope of the prior art.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination, a car truck having a sprung part and an unsprung part movable to different positions relative to each other according to the load on the truck, a rail brake element, two levers pivotally connected to each other intermediate the ends thereof, one of said levers supporting said rail brake element, the said two levers being so arranged as to assume different angles with respect to each other according to the relative position .of the sprung and unsprung parts of the said truck and thereby cause the said one lever to maintain the said rail brake element normally in a position which is a substantially constant distance above a cooperating track rail for any load carried on the truck.

2. In combination, a car truck having a sprung part and an unsprung part adapted to have different relative positions according to the load carried by the truck, a rail brake element, a iirst lever pivoted at one end on the unsprung part of the truck and pivotally movable through an arc to different positions according to the position of the sprung part of the truck relative to the unsprung part, asecond lever pivoted at one end on the sprung part of the truck and having pivotal connection with said first lever at a point intermediate the ends of said first lever, said second lever being arranged to support said rail brake shoe, the said first land said second levers being arranged so that upon relative movement between the sprung and unsprungr parts of the. truck, the said second lever maintains the rail brake element` at a substantially constant elevation above an associated track rail.

3. In combination, a car truck having a sprung part and an unsprung part adapted to have different relative positions according to the load on the truck, a rail brake element, a rst bellcrank lever pivoted at the fulorum thereof on the unsprung part of said truck and having one arm pivoted on the sprung partof said truck, a second bell-crank lever pivoted at the fulcrum thereof on the sprung part of said truck and having one arm thereof arranged to support said rail brake element, means connecting the other arm of the first bell-crank lever to the other arm of the said second-bell crank lever, the arrangement of said bell-crank levers being such that the arm of the second bell-crank lever which supports the rail brake element is always posi tioned so `as to maintain the rail brake elements normally a substantially constant distance above an associated track rail.

4. In combination, a car truck having a sprung part and an unsprung part adapted to have different positions relative to each other according to the load on the truck, a rail brake element, two bell-crank levers the corresponding arms of which are proportional in length, one of said levers being pivoted at the fulcrum thereof on the unsprung Vpart vof the truck and having one arm the other of said levers being pivoted at the fulcrum thereof on the sprung part vof the truck and having one arm thereof arranged to support said rail brake element, means connecting'the,

other arm of the rst said lever to the other arm of the said other lever, the arrangement of 'said levers being such that upon relative movement between the sprung and the unsprung parts of the truck, the arm of the said second lever which supports therail brakey element is always positioned so'as to support the rail brake element a substantially constant distance above an associated track rail.

5. In combination, a' vehicle truck having a sprung part and an'unsprung part adapted to have different relative positions according to the load on the truck, a rail brake element, an element for supporting the said rail brake element, a

cam element arranged to support said element on the sprung part of said truck and effective upon rotation to vary the position of said element relative to the sprungpart of the truck, and means for rotating said cam element correspondingly upon variation in the relative position between the sprung andfunsprung parts on the said truck to maintain the said supporting element for the rail brake element at asubstantially constant elevationvso that the railbrake element is main- 'tained a ksubstantially constant distance. away from the associated track rail for any load on the truck.

6. In combination, a vehicle truck having a sprung part and an unsprung part adapted to have diierent relative positions according to the load on the truck, a rail brake element, an element for supporting the said rail brake element, a cam element arranged to support said element on the sprung part of said truck andveffective upon rotationl to vary the position of said element relative to the sprung part of the truck,

and means for rotarily positioning said cam ele# ment according to the relative position of the sprung and unsprung parts of the truck so as to maintain the said element at a substantially constant level vand thereby cause the rail brake element to be maintained normally a substantially constant distance above the associated track rail for any load on the truck.v

'7. A magnetic track brake for ak vehicle truck havingboth sprung and unsprung parts, comprising in combination,` a ilrst lever pivotally mounted on an unsprung part of the truck, a second lever pivotally mounted on a sprung part of the truck, a `magnetic track brake device, means for suspending said magnetic track brake device from one of said levers in a manner to permit movement of the brake device relative to said one lever so that said brake device may be shifted into engagement with a track rail without movement of said one lever when applying the brakes,

1 and means so relating said two levers that said v movement between the said sprung and unsprung parts. n y

CLYDE C. FARMER. 

